Sulfur transfer reaction from phosphine sulfides to phosphines assisted by metal ions

Article abstract of DOI:10.1016/j.ica.2011.11.049

The sulfur transfer reaction from phosphine sulfides to various phosphines in the presence of metal ion was studied; in the presence of Cu(I), a sulfur transfer reaction from dppmS₂ (bis(diphenylphosphino)methane disulfide) to dppm (bis(diphenylphosphino)methane) or to dppa (bis(diphenylphosphino)amine) occurs and the product [Cu(dppmS) ₂]⁺ (1) and [Cu(dppmS)(dppaS)]⁺ (2) was obtained quantitatively. In the presence of Zn(II), sulfur transfer to various phosphines can be carried out catalytically. The reaction mechanism has been proposed from the difference in the reactivity of diphosphines and metal ions.

Full text of DOI:10.1016/j.ica.2011.11.049

Inorganica Chimica Acta 384 (2012) 149–153
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Inorganica Chimica Acta
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Sulfur transfer reaction from phosphine sulfides to phosphines assisted
by metal ions
⇑
Toshiaki Tsukuda , Risa Miyoshi, Akiko Esumi, Akira Yamagiwa, Ayumi Dairiki, Kenji Matsumoto,
⇑
Taro Tsubomura
Department of Materials and Life Science, Seikei University, Tokyo 180-8633, Japan
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 9 June 2011
Received in revised form 16 November 2011
Accepted 16 November 2011
Available online 25 November 2011
The sulfur transfer reaction from phosphine sulfides to various phosphines in the presence of metal ion was
studied; in the presence of Cu(I), a sulfur transfer reaction from dppmS2 (bis(diphenylphosphino)methane
disulfide) to dppm (bis(diphenylphosphino)methane) or to dppa (bis(diphenylphosphino)amine) occurs
and the product [Cu(dppmS)2]+ (1) and [Cu(dppmS)(dppaS)]+ (2) was obtained quantitatively. In the pres-
ence of Zn(II), sulfur transfer to various phosphines can be carried out catalytically. The reaction mecha-
nism has been proposed from the difference in the reactivity of diphosphines and metal ions.
Ó 2011 Elsevier B.V. All rights reserved.
Keywords:
Phosphine sulfide
Sulfur transfer reaction
d10 Metal complexes
Catalytic reactions
X-ray crystallography
1. Introduction
chalcogenides (R3P@X, X = O, S, and Se). As for similar chalcogen
transfer reactions, it has been reported that phosphine telluride
Over the past several decades, diphosphine disulfide ligands
(Scheme 1, above), which can be considered to be inorganic ana-
logues of b-diketonate, have been studied extensively in the coor-
dination chemistry of both main group and transition metals [1].
The widespread interest in their complexes arises from a number
of potential use, e.g., as lanthanide shift reagents [2], in metal
extraction processes [3], or as sulfur source for the production of
nano-scale semiconducting metal sulfides [4]. In addition, since
phosphine sulfides containing pentavalent phosphorus atoms are
more stable toward oxidation than trivalent phosphine derivatives
and sulfur atoms can function as soft donors like phosphorus ones,
phosphine sulfides are useful as the alternatives of phosphine
ligands in order to form stable functional materials. Reigle et al.
and our group have reported the luminescence of several com-
plexes with phosphine sulfides [5,6].
is decomposed into the corresponding phosphine and elemental
tellurium in the presence of Lewis acid and reversible chalcogen
transfer from phosphine telluride or selenide to free phosphines
occurs [8]. In addition, sulfur transfer reactions from thiophos-
phates or metal sulfides also have been reported [9].
Previously, it has been reported that the mixed-ligand dinuclear
Cu(I) complex, [Cu2(phen)2(dppm)2](PF6)2, which is bridged by
dppm, is readily obtained by treatment of Cu(I) ion and 1,10-
phenanthroline (phen) with an equimolar amount of dppm [10].
Therefore we expected that the use of diphosphine disulfide
instead of the phen ligands would give the mixed-ligand Cu(I)
complexes, such as [Cu2(dppmS2)2(dppm)2]2+. Attempt to prepare
such mixed-ligand Cu(I) complexes failed. Instead, we found novel
sulfur transfer reactions mediated by copper(I) and zinc(II) com-
plexes. In this report, sulfur transfer reactions from phosphine
sulfides to free phosphines (as shown in Scheme 1, below) in the
presence of Cu(I) or Zn(II) ion have been described and the mech-
anism of the reactions have been discussed. Reaction of copper
complexes affords quantitative production of phosphine sulfides;
on the other hand, the use of Zn(II) ion gives catalytic reactions.
Though the phosphine sulfide group is not a strong
r-donor, the
unoccupied p⁄ orbital is positioned in a moderately low energy-
level and thus can effectively accept electrons to stabilize metals
in the low oxidation state, e.g., Pd(0). Aizawa et al. reported cata-
lytic activity of Pd(0) complexes bearing phosphine sulfides for
some coupling reactions [7]. In their work, it was also shown that
Pd(0) promotes chalcogen atom replacement of phosphine
2. Experimental
⇑
Corresponding authors. Tel./fax: +81 55 220 8235 (T. Tsukuda). Present address:
Faculty of Education and Human Sciences, University of Yamanashi. Tel./fax: +81
422 37 3752 (T. Tsubomura).
2.1. General
All reactions were carried out under Ar atmosphere by using
Schlenk technique. Diphosphines (Scheme 1, below) and zinc salts
E-mail addresses: ttsukuda@yamanashi.ac.jp (T. Tsukuda), tsubomura@st.sei-
kei.ac.jp (T. Tsubomura).
0020-1693/$ - see front matter Ó 2011 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2011.11.049

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T. Tsukuda et al. / Inorganica Chimica Acta 384 (2012) 149–153
2.4. Catalytic reaction in the presence of Zn(II) ion
Ph Ph
P
S
2.4.1. Initial screening of the catalytic activity of zinc salt
dppmS2
H2C
Dppm (2.0 mmol) and dppmS2 (0.81 g 1.8 mmol) was dissolved
in acetone (50 ml), and then zinc salt (2.5 mol%, Zn(CF3SO3)2,
Zn(BF4)2, ZnCl2, ZnBr2 or ZnF2) was added to the solution. The mix-
ture was continuously stirring for 24 h at room temperature under
dark conditions to prevent oxidation of phosphine moieties by a
trace amount of oxygen dissolved in the solution. The solution
was evaporated to dryness. The semi-quantitative product yields
were estimated from the integrated area of the corresponding 31P
NMR signals assigned to dppm(d À22.1), dppmS(d 41.2 and
À27.8) and dppmS2 (d 35.8) of the resultant powder dissolved in
acetone-d6.
P
S
Ph Ph
Ph2P
PPh2
Ph2P
PPh2 n= 1: dppm
2: dppe
N
H
n
3: dppp
4: dppb
dppa
2.4.2. Quantitative analysis of the reactivity of diphosphine and
dppmS2
Ph2P
PPh2
O
First, the solutions of the accurately weighed amount of dppmS
or dppmS2 (5, 10 and 15 mg) was put into NMR sample tube
including a capillary in which a small amount of 85% H3PO4 as
standard was encapsulated, and then the relative sensitivity of
the two compounds was calculated from the ratio of an integrated
areas of the signals assigned to dppmS or dppmS2 to that at d 0 in
31P NMR spectra. Diphosphine (2.0 mmol) and dppmS2 (0.81 g
1.8 mmol) were dissolved in acetone (50 ml), and then Zn(CF3SO3)2
(65 mg, 10 mol%) was added to the solution. After stirring for 24 h
at room temperature under dark conditions, the solution was evap-
orated to dryness. A weighed amount of the obtained white
mixture (ca. 10 mg) was dissolved in acetone-d6 and then mea-
surement of 31P NMR was carried out. Since no signals were
observed except the unreacted reactants and products (i.e., diphos-
phine monosulfide), the sum of molar amounts of dppmS or
dppmS2 estimated from each integrated value should be almost
equal to the amount of initial dppmS2. So conversion yield was
estimated by the ratio of the amount of dppmS to that of initial
dppmS2.
cis-dppet
PPh2
PPh2
DPEphos
PPh2
Ph2P
PPh2
Ph2P
trans-dppet
dppbz
Scheme 1.
were purchased by WAKO Co. Ltd. and Aldirich Co. Ltd., and used
without further purification. Bis(diphenylphosphino)methane
disulfide (dppmS2) [11] and [Cu(CH3CN)4]PF6 [12] were obtained
according to the procedures described. NMR spectra were obtained
using a JEOL
enced by using tetramethylsilane (1H; as internal) or 85% H3PO4
31P{1H}; as external).
K-400 spectrometer, and chemical shifts are refer-
(
2.5. X-ray measurements
Single crystals suitable for X-ray analysis for 1, 2 and 3 are
obtained by slow diffusion of diethyl ether in acetone solution.
X-ray crystallographic measurements were made on a Rigaku Sat-
2.2. Reaction of dppm with dppmS2 in the absence of metal ions
Dppm (76 mg, 0.2 mmol) and dppmS2 (90 mg, 0.2 mmol) was
dissolved in acetone (5 ml). After stirring the mixture for a day,
the solution was evaporated to dryness under reduced pressure.
The 31P NMR spectrum of the obtained white powder dissolved
in CDCl3 was measured.
urn 70 CCD area detector with graphite-monochromated MoK
a
radiation. The crystal-to-detector distance was 54.90 mm. The data
were collected at a temperature of 150 1 K and processed by
using CrystalClear software [13]. Absorption corrections were
made by numerical methods. The structures were solved by direct
methods (SIR-92 [14] or SIR 2004 [15]) and were refined by full ma-
trix least squares procedures (SHELXL-97 [16]). The non-hydrogen
atoms are refined anisotropically and the positions of all hydrogen
atoms were fixed at calculated positions. All calculations were per-
formed by using the CrystalStructure crystallographic software
package [17].
2.3. Stoichiometric reactions in the presence of Cu(I) ion
Each diphosphine (dppm, dppa or dppp: 0.2 mmol) and dppmS2
(90 mg 0.2 mmol) was added to the solution of [Cu(CH3CN)4]PF6
(75 mg, 0.2 mmol) in acetone (5 ml) at room temperature. After
stirring the mixture for 1 h, diethyl ether (ca. 15 ml) was added
to the solution. The white powder precipitated was collected by fil-
tration. [Cu(dppmS)2]PF6 (140 mg, 67%) was obtained using dppm
as starting diphosphine, Anal. Calc. for [C50H44P4S2Cu]PF6: C, 57.66;
H, 4.26. Found: C, 57.01; H, 4.57%.
3. Results and discussion
3.1. Reactions of dppmS2 with several diphosphines in the presence of
Cu(I) ion
[Cu(dppaS)(dppmS)]PF6: 130 mg was obtained by using dppa.
Anal. Calc. for [C49H43NP4S2Cu]PF6Á(CH3)2CO: C, 56.75; H, 4.49; N,
1.27. Found: C, 56.39; H, 4.86; N, 1.43%. [Cu(dppmS2)(dppp)]PF6:
168 mg (79%) was obtained by using dppp. Anal. Calc. for
[C52H48P4S2Cu]PF6: C, 58.40; H, 4.52. Found: C, 58.67; H, 4.00%.
Recrystallization can be carried out for these complexes in
acetone/diethyl ether.
Treatment of [Cu(I)(CH3CN)4] ion and dppmS2 with equimolar
amounts of dppm at room temperature gave an unexpected homo-
leptic product, [Cu(dppmS)2]PF6 (1), in which a sulfur atom of
dppmS2 was transferred to a dppm ligand. The transfer reaction
occurs almost quantitatively, therefore complex 1 can be isolated
in good yield (67%). The 31P{1H} NMR spectrum of complex 1 in

T. Tsukuda et al. / Inorganica Chimica Acta 384 (2012) 149–153
151
absence of Cu(I) ion gave the solution, the 31P{1H} NMR of which
showed only two distinct singlet signals assigned to each com-
pound (d 35.8 and À20.2), whereas no signal assigned to dppmS
was observed even after a day. This shows that the sulfur transfer
reaction from dppmS2 to dppm does not occur in the absence of the
Cu(I) ion.
The structural details of 1 were determined by single crystal
X-ray diffraction (Fig. 1). Actually, two dppmS ligands are coordi-
nated to the copper center in a five-membered chelate fashion.
The complex of the perchlorate salt was already obtained by a
treatment of [Cu2(CH3CN)4(dppm)2]2+ with CS2 as previously re-
ported [19], however, disorder of one phenyl group was observed
in the previous crystal structure analysis. The R factor in our result
(R1 = 4.5%) is considerably smaller than that of the previous report
(R1 = 9.1%). Crystallographic data are shown in Table 1 and selected
bond distances and angles are summarized in Table 2. The P–S
bond lengths ranging from 1.9769(9) to 1.9862(9) Å show that
the bonds almost have double bond character [6,20]. The five-
membered chelate angles of P(1)–Cu(1)–S(3) and P(2)–Cu(1)–S(4)
are 97.39(3)° and 94.49(2)°, respectively.
Fig. 1. ORTEP structure of the diphosphine monosulfide complex cation,
[Cu(dppmS)2]+ (1).
The use of dppa, in which diphenylphosphino groups are
bridged by an amino group instead of a methylene group, gave a
heteroleptic complex, [Cu(dppmS)(dppaS)]+ (2), in which sulfur
transfer reaction from dppmS2 to dppa also occurs and thus the
structure of complex 2 should be similar to that of complex 1. In
the 31P NMR spectrum of the products (Fig. S1(b)), a multiplet sig-
nal at d 50.0 and a broad signal at d À11 are assigned to the dppmS
moiety from a comparison with the spectrum of complex 1. In
addition, the spectrum exhibits another couple of a multiplet sig-
nal and a broad signal occurring at d 67.8 and d 32, respectively.
The signals are assigned to dppaS. The multiple splitting of the
lower-field signals shows the presence of the coupling to the other
three phosphorus atoms in different environments and thus it
shows the presence of heteroleptic cation 2 even in solution.
On the other hand, treatment of dppp with dppmS2 and Cu(I)
ion gave a heteroleptic complex, [Cu(dppp)(dppmS2)]+ (3), in
which transfer of sulfur from dppmS2 to dppp does not occur.
Unlike the case of complex 1 and 2, the 31P{1H} NMR spectrum
of complex 3 in CDCl3 exhibits a triplet signal at d 35 (J = 17 Hz)
assigned to the pentavalent phosphorus on dppmS2 and a broad
signal at d À16 assigned to trivalent phosphorus directly coordi-
nated to the Cu(I) ion (Fig. S1(c)). The crystal structure obtained
by X-ray analysis also shows the formation of the heteroleptic
complex. Structural details are shown in Fig. 2 and selected bond
Table 1
Crystallographic data for 1 and 3.
1
3
Formula
Formula weight
Crystal size
T (K)
Crystal system
Space group
a (Å)
C
52H47CuF6P5S2O
C53H50CuF6P5S2Cl2
1154.41
0.20 Â 0.12 Â 0.12
123
monoclinic
Cc (#9)
26.137 (2)
12.7462 (9)
17.707 (2)
90
110.792 (1)
90
5515.0 (8)
4
1.390
7.685
0.085
1057.42
0.35 Â 0.23 Â 0.20
123
triclinic
P-1 (#2)
11.069 (4)
11.900 (4)
19.200 (6)
91.804 (4)
105.228 (5)
91.062 (4)
2438.1 (13)
2
b (Å)
c (Å)
a
(°)
b (°)
c
(°)
V (Å3)
Z
Dcalc (g/cm3)
1.440
7.58
0.045
0.121
l
(cmÀ1
)
R1
wR2
0.248
CDCl3 exhibits two signals at d 50.0 (dd, J = 60 and 34 Hz) and
À10.9(br) (Fig. S1(a)). The signal broadening in the higher field res-
onance assigned to a trivalent phosphine group may be caused by
quadrapolar relaxation of the copper nucleus on direct coordina-
tion of phosphine, which has been observed for some Cu(I)–phos-
phine complexes [18]. The signal lying in the lower field, which is
typical of the pentavalent phosphorus in P@S groups, shows dou-
blet of doublet splitting by coupling with two phosphorus atoms;
one is on the same ligand and the other is on the ligand coordinat-
ing on the opposite site. Treatment of dppmS2 and dppm in the
Table 2
Selected bond lengths (Å) and angles (°) and torsion angles (°) for 1.
Cu–S(1)
Cu–P(3)
S(1)–P(1)
2.3813(8)
2.2526(7)
1.9769(9)
Cu–S(2)
Cu–P(4)
S(2)–P(2)
2.4041(6)
2.2618(8)
1.9862(9)
S(1)–Cu–S(2)
S(1)–Cu–P(3)
S(2)–Cu–P(3)
Cu–S(1)–P(1)
Cu–P(3)–C(1)
104.26(3)
P(3)–Cu–P(4)
S(1)–Cu–P(4)
S(2)–Cu–P(4)
Cu–S(2)–P(2)
Cu–P(4)–C(2)
135.35(3)
97.39(3)
112.82(3)
95.32(3)
109.68(3)
94.49(2)
91.49(3)
106.0(1)
105.70(9)
Cu–S(1)–P(1)–C(1)
S(1)–P(1)–C(1)–P(3)
Cu–P(3)–C(1)–P(1)
À43.2(1)
43.7(2)
À18.2(2)
Cu–S(2)–P(2)–C(2)
S(2)–P(2)–C(2)–P(4)
Cu(1)–P(4)–C(2)–P(2)
À53.33(8)
46.2(1)
À10.7(1)
Fig. 2. ORTEP structure of the heteroleptic complex cation, [Cu(dppmS2)(dppp)]+
(3).

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T. Tsukuda et al. / Inorganica Chimica Acta 384 (2012) 149–153
Table 3
In addition, unlike the case of copper(I) ion, the reaction of
dppmS2 with various phosphines in the presence of the zinc salts
also afforded the corresponding diphosphine monosulfide (Table
1). The conversion yield of dppe was estimated to be 87% (Table
4, entry 2 and Fig. S6). The increase in the length of the carbon
chain bridging the two phosphorus atoms leads to a decrease of
the yield of monophosphine sulfide (entry 3–4). In the reaction
with dppb, the conversion yield decreases to 16%. However, DPE-
phos, which is bridged by four carbons and one oxygen between
the two phosphorus atoms, gave a moderate conversion yield
(47%, Table 4, entry 5 and Fig. S6(b)). The use of cis-dppet results
in further decrease of the yield compared with the case of dppe
(16%, entry 6). No transfer reaction to trans-dppet or dppbz oc-
curred (Table 4, entry 7, 8 and Fig. S6(c)). Reaction of dppmS2 with
two equivalent of Ph3P readily produces Ph3P@S (Fig. S6(d)). How-
ever, production of a small amount of dppm shows sulfur transfer
reaction from dppmS can occur slightly.
Selected bond lengths (Å) and angles (°) and torsion angles (°) for 3.
Cu(1)–S(1)
Cu(1)–P(3)
S(1)–P(1)
2.3933(19) Cu(1)–S(2)
2.3266(18)
2.248(2)
1.977(3)
2.266(2)
1.973(2)
Cu(1)–P(4)
S(2)–P(2)
S(1)–Cu–S(2)
S(1)–Cu–P(3)
S(2)–Cu–P(3)
Cu–S(1)–P(1)
Cu–P(3)–C(50)
102.64(6)
102.90(7)
127.82(8)
103.01(10)
105.4(3)
P(3)–Cu–P(4)
S(1)–Cu–P(4)
S(2)–Cu–P(4)
Cu–S(2)–P(2)
Cu–P(4)–C(52)
100.67(8)
110.15(8)
111.85(8)
100.44(9)
105.7(3)
Cu–S(1)–P(1)–C(25)
S(1)–P(1)–C(25)–
P(2)
À22.9(3)
Cu–S(2)–P(2)–C(25)
S(2)–P(2)–C(25)–
P(1)
À35.0(2)
À35.6(4)
73.6(4)
lengths and angles are shown in Table 3. Each dppp and dppmS2
ligand was coordinated to the Cu(I) ion in a chelate fashion. The
P-S bond lengths of the complexes range from 1.973(2) to
1.977(3) Å, which are consistent with double bond character of
the P@S bonds. However, the bond lengths are slightly longer than
those in a free dppmS2 ligand (1.941(1) and 1.948(1) Å) [21],
suggesting that the P@S bonds are somewhat weakened. The six-
membered chelate angles of P(1)–Cu(1)–P(2) and S(1)–Cu(1)–S(2)
are 102.64(6)° and 100.67(8)°, respectively. The reaction of dppe
or dppbz instead of dppp gave similar results; i.e., the sulfur trans-
fer reaction does not occur (Fig. S2).
Sulfur transfer reaction of dppmS2 with monophosphine in the
presence of Cu(I) ion hardly occurred. 31P NMR spectra of the prod-
ucts after the reaction of 3 h at room temperature shows that little
transformation of Ph3P to PPh3P@S is observed and that the utiliza-
tion of Ph2Ppy leads to no sulfur transfer reaction (Fig. S3).
3.3. Mechanism for sulfur transfer reaction of dppmS2 with several
diphosphines in the presence of metal ion
As described above, sulfur transfer reaction from the phosphine
sulfides, dppmS2, to free phosphines can be carried out in the pres-
ence of Cu(I) and Zn(II) ions, whereas no reaction occurs on treat-
ment of the substrates without metal ions. Interestingly, it was
found that the reaction mode of the sulfur transfer depends not
only on the metal ions used but also on the phosphines. When
dppm or dppa is used as phosphine, sulfur transfer reaction always
occurs. In the presence of Cu(I), phosphine monosulfide complex 1
and 2 are obtained quantitatively. In the presence of Zn(II), cata-
lytic sulfur transfer reactions have been observed. However, in
the cases of dppe, dppp or dppbz, the results depends on the metal
ions: the mixed-ligand Cu(I) complexes have been isolated without
causing sulfur transfer. In the presence of Zn(II) ion, the transfer
reaction from dppmS2 to the diphosphines bridged by methylene
groups proceeds catalytically. In the cases of dppbz, no sulfur
transfer reactions have been observed in the presence of either
Cu(I) or Zn(II) ion.
The trend in the reactivity of the sulfur transfer seems to show
that the use of diphosphines which can readily coordinate to a me-
tal center in a chelate fashion prevents the sulfur transfer reaction.
The dppm ligand is known to have less ability to make a chelate.
On the other hand, dppbz is likely to coordinate only in a chelate
fashion.
For the chalcogen transfer reactions from phosphine chalcoge-
nides to phosphines, the associative mechanism involving the at-
tack of the phosphorous atom on the sulfur atom to give a P–S–P
intermediate has been proposed by means of theoretical calcula-
tions and kinetic measurements (Scheme S1) [9,22]. The mecha-
3.2. Catalytic reaction of dppmS2 with several diphosphines in the
presence of Zn(II) ion
The use of Zn(II) ion instead of Cu(I) ion also gave dppmS by sul-
fur transfer reaction from dppmS2 to dppm. However, the transfer
reaction can be carried out catalytically unlike the case of the Cu(I)
ion. Even in the presence of a small amount of Zn(CF3SO3)2
(2.5 mol%) at room temperature, dppmS produced by the sulfur
transfer reaction was readily obtained by the reaction of dppm
and dppmS2 (Fig. S4). After the reaction for 20 h in the presence
of 10 mol% Zn(CF3SO3)2, the 31P NMR spectrum of the reaction
solution shows that the catalytic reaction has been completed
quantitatively (entry 1 in Table 4) and the dppmS was isolated in
58% yield after recrystallization. Using Zn(BF4)2 instead of
Zn(CF3SO3)2 also gave dppmS in a comparable yield. However, zinc
halides did not act as good catalysts. In the presence of ZnCl2 or
ZnBr2, only about a half amount of dppmS was obtained even by
reaction for three days as compared with the triflate, and no sulfur
transfer reaction occurs in the presence of ZnF2 (Fig. S5).
nism requires an uncoordinated phosphorus atom of
a
diphosphine ligand in the intermediate of the sulfur-transfer reac-
tion. This seems to be consistent with the trend of the reactivity of
the phosphines described above.
The tentative reaction mechanism is shown in Scheme 2. The
diphosphine disulfides and diphosphines successively coordinate
to the metal ion. At this stage, if Cu(I) and chelating phosphines
are used, simple heteroleptic complexes are obtained. If the
diphosphines do not seem to form stable chelates, sulfide transfer
occurs to give complexes coordinated by two diphosphine mono-
sulfides. In the presence of Cu(I), the phosphine monosulfide com-
plex is thus readily obtained. On the other hand, the harder Zn(II)
ion coordinates to the phosphine monosulfide ligands more
weakly, thus the free diphosphine monosulfides are released from
the complex. It is well known that the coordination bond between
zinc and phosphorus atoms has a greater tendency to dissociate in
solution [23].
Table 4
Conversion yields on catalytic sulfur transfer reaction of dppmS2 to various
phosphines in the presence of 10 mol% Zn(CF3SO3)2 at room temperature.
Entry
Diphosphine
Conversion yield (%)a
1
2
3
4
5
6
7
8
dppm
dppe
dppp
dppb
DPEphos
cis-dppet
trans-dppet
dppbz
96
87
45
16
47
16
0
0
a
Estimated yields by integral values in 31P NMR.

T. Tsukuda et al. / Inorganica Chimica Acta 384 (2012) 149–153
153
Ph
Ph
Ph Ph
P
P
S
S
n+
M
H2C
+
Ph
X
Ph
S
P
S
P
P
P
P
Ph
Ph
Ph Ph
Cu
P
Ph
In the presence of Zn(II)
(catalytic reaction)
S
Ph
P
P
S
H2C
M
dppm, in the presence of Cu(I)
(stoichometric reaction)
S
Ph
Ph
P
P
Ph
P
Ph
P
S
M
H2C
Ph Ph
P
P
S
P
S
S
Ph
Ph
H2C
P
Ph
M
Sulfur transfer
Ph
P
P
Ph Ph
P
P
P
S
S
dppp in the presence of Cu(I)
(No transfer reaction)
H2C
Cu
P
Ph Ph
Scheme 2.
[3] J.G.H. du Preez, K.U. Knabl, L. Krüger, B.J.A.M. van Brecht, Solvent Ectr. Ion Exch.
10 (1992) 729.
4. Conclusion
[4] (a) M. Afzaal, K. Ellwood, N.L. Pickett, P. O’Brien, J. Raftery, J. Waters, J. Mater.
Chem. 14 (2004) 1310;
It has been found that sulfur transfer reactions from a phos-
phine sulfide (dppmS2) bridging by a methylene group to various
phosphines occur in the presence of metal ions. In the presence
of Cu(I), dppmS2 and diphosphine bridged by a methylene or an
amino group (dppm or dppa), underwent quantitative formation
of four-coordinate complexes coordinated by two diphosphine
monosulfides. Sulfur transfer reaction from dppmS2 to dppp did
not occur in the presence of Cu(I), but a simple heteroleptic com-
plex, [Cu(dppp)(dppmaS2)]+, was obtained. In the presence of Zn(II)
ion, the transfer reaction from dppmS2 to many diphosphines ex-
cept dppbz and trans-dppet proceeds catalytically. The difference
in the reactivity of the diphosphines suggests that the tendency
to make chelates is one of the key factors to accept a sulfur atom
for diphosphine ligands.
Another important result in this study is the quantitative for-
mation of [Cu(dppmS)2]. This may be due to the fact that the prod-
uct has stable five-membered chelates as compared to the starting
ligands dppmS2 and dppm, which potentially make less stable se-
ven- and four-membered chelates. The Cu(I) complex is also of
importance from the point of view that the complexes can be re-
garded as an intermediate in the catalytic system mediated by
the Zn(II) ion.
(b) M. Afzaal, D. Crouch, P. O’Brien, J.-H. Park, J. Mater. Sci.: Mater. Elecron. 13
(2003) 555.
[5] (a) R.K. Reigle, D.J. Casadonte Jr., S.G. Bott, J. Chem. Crystallogr. 24 (1994) 753;
(b) R.K. Reigle, D.J. Casadonte Jr., S.G. Bott, J. Chem. Crystallogr. 24 (1994) 769.
[6] A. Dairiki, T. Tsukuda, K. Matsumoto, T. Tsubomura, Polyhedron 28 (2009)
2730.
[7] (a) S. Aizawa, A. Majumder, Y. Yokoyama, M. Tamai, D. Maeda, A. Kitamura,
Organometallics 28 (2009) 6067;
(b) S. Aizawa, A. Majumder, D. Maeda, A. Kitamura, Chem. Lett. 38 (2009) 18;
(c) S. Aizawa, M. Tamai, M. Sakuma, A. Kubo, Chem. Lett. 36 (2007) 130.
[8] (a) C. Daniliuc, C. Druckenbrodt, C.G. Hrib, F. Ruthe, A. Blaschette, P.G. Jones,
W.-W. du Mont, Chem. Commun. (2007) 2060;
(b) A.M. Brondie, G.A. Rodley, C.J. Wilkins, J. Chem. Soc. A (1969) 2927;
(c) W.-W. du Mont, Z. Naturforsch. B: Anorg. Chem. Org. Chem. 40 (1985)
1453;
(d) W.-W. du Mont, H.J. Kroth, J. Organomet. Chem. 113 (1976) C35.
[9] (a) A.A. Eagle, R.W. Gable, S. Thomas, S.A. Sproules, C.G. Young, Polyhedron 23
(2004) 385;
(b) W. Adam, R.M. Bargon, Chem. Commun. (2001) 1910.
[10] (a) S. Kitagawa, H. Maruyama, S. Wada, M. Munakata, M. Nakamura, H.
Masuda, Bull. Chem. Soc. Jpn. 64 (1991) 2809;
(b) T. Tsukuda, A. Nakamura, T. Arai, T. Tsubomura, Bull. Chem. Soc. Jpn. 79
(2006) 288.
[11] I. Haiduc, I. Silaghi-Dumitrescu, Coord. Chem. Rev. 74 (1986) 127.
[12] G.J. Kubas, Inorg. Synth. 19 (1979) 90.
[13] CrystalClear, Area Detector Processing Software: Rigaku and Molecular
Structure Corp., 2000.
[14] SIR-92: A. Altomare, M.C. Burla, M. Camalli, M. Cascarano, C. Giacovazzo, A.
Guagliardi, G. Polidori, M. Camalli, J. Appl. Crystallogr. 27 (1994) 435.
[15] SIR-2004: M.C. Burla, R. Caliandro, M. Camalli, B. Carrozzini, G.L. Cascarano, L.
De Caro, C. Giacovazzo, G. Polidori, R. Spagna, J. Appl. Crystallogr. 38 (2005)
381.
Appendix A. Supplementary material
[16] G.M. Sheldrick, SHELXL-97: Program for Crystal Determination and Refinement,
University of Göttingen, Germany, 1997.
[17] Crystal Structure, ver.4.00: Single Crystal Structure Analysis Software,
Molecular Structure Corporation.
Supplementary data associated with this article can be found, in
the online version, at doi:10.1016/j.ica.2011.11.049.
[18] B. Mohr, E.E. Brooks, N. Rath, E. Deutsch, Inorg. Chem. 30 (1991) 4541.
[19] C. Sivasankar, J.K. Bera, M. Nethaji, A.G. Samuelson, J. Organomet. Chem. 689
(2004) 2726.
References
[20] T.S. Lobana, Prog. Inorg. Chem. 37 (1989) 495 (and references herein).
[21] C.J. Carmalt, A.H. Cowley, A. Decken, Y.G. Lawson, N.C. Norman, Acta
Crystallogr., Sect. C 52 (1996) 931.
[22] M. Kullberg, J. Stawinsky, J. Organomet. Chem. 690 (2005) 2571.
[23] T. Tsukuda, C. Nishigata, K. Arai, K. Matsumoto, T. Tsubomura, Polyhedron 28
(2009) 7.
[1] For reviews, see: (a) C. Silvestru, J.E. Drake, Coord. Chem. Rev. 223 (2001) 117;
(b) T.Q. Ly, J.D. Woollins, Coord. Chem. Rev. 176 (1998) 451;
(c) I. Haiduc, in: J.A. McCleverty, T.J. Meyer (Eds.), Comprehensive
Coordination Chemistry II, Elsevier Ltd., Amsterdam, 2003, p. 323.
[2] H. Rudler, B. Denise, J.R. Gregorio, J. Vaissermann, Chem. Commun. (1997)
2299.